Congolese investigators planned Sunday to head to the site of a plane crash in the centre of the country that killed all 22 people on board.

The government confirmed that the aircraft went down late Saturday afternoon, shortly after taking off from the city of Boende.

But officials did not say whether the plane, a Soviet-made Antonov 26, was carrying civilians or soldiers.

The United Nations said the aircraft was not being used by its staff. The UN is monitoring a ceasefire in the Democratic Republic of Congo.

The crash site is about 900 kilometres northeast of the capital city, Kinshasa.

Congo, formerly Zaire, is a large African country with few paved roads. People rely heavily on boats and planes to get around.